Black men who have sex with men (MSM) bear the greatest burden of HIV across all races/ethnicities and risk groups, accounting for ~40% of diagnoses among MSM of all races/ethnicities, and one-third among all men. Compared to other races/ethnicities, Blacks living with HIV are less likely to be diagnosed, to be engaged in care, and to receive and adhere to antiretroviral treatment (ART). Black MSM in particular show very low ART adherence. In this 3-year intervention development study, we propose to develop and pilot test a culturally relevant intervention to reduce medical mistrust and address discrimination among Black MSM living with HIV. Our work with Black MSM suggests that culturally relevant factors such as perceived discrimination and HIV- related medical mistrust (e.g., HIV conspiracy beliefs, like HIV is a manmade virus) contribute to disparities in HIV treatment behaviors, in some cases even more than factors known to be highly influential like depression and substance use. Black MSM living with HIV are at the nexus of 3 stigmatized social categories (HIV-serostatus, race, sexual orientation) from which they face discrimination, which in turn can lead to disparities by increasing detrimental stress responses related to poor self-control (maladaptive coping, poor health behaviors). Discrimination also fosters mistrust of public health entities, and suspicion of medical treatments. However, no interventions have been developed to overcome these culturally relevant barriers. In the proposed innovative community-based participatory research project, we will partner with a Black-MSM- serving AIDS service organization (ASO) with high success in engaging Black MSM in research. In Phase 1, we will conduct qualitative interviews with 30 Black MSM and 20 social service and mental health providers, and engage stakeholders in a community advisory process to obtain input on sustainable intervention components that can improve the effectiveness of service delivery. In Phase 2, we will conduct a process evaluation of one pilot intervention group of 10 participants, delivered via a community HIV support group. In Phase 3, we will conduct a small randomized pilot trial with 3 intervention groups and 3 control groups (10 participants each). The specific aims are to: 1. Conduct qualitative semi-structured interviews with Black MSM, and engage AIDS service organization (ASO) staff and mental health counselors, in order to develop intervention modules that address mistrust and discrimination among Black MSM. 2. Examine whether the pilot intervention can reduce mistrust and improve coping responses to discrimination among Black MSM. 3. Explore pilot intervention effects on mental health, antiretroviral treatment adherence, and engagement in care among Black MSM. Our goal is for the proposed culturally relevant intervention to be exportable to interventions already developed for improving adherence and engagement in care among people living with HIV. If shown to be effective in future R01-funded research, our intervention will be flexible for use in community settings, such as in existing HIV support groups already being sustained throughout the US.